Beyond dRGT as Mimetic Massive

TL;DR

This paper shows that extending dRGT massive gravity via disformal transformations can be viewed as a mimetic extension, simplifying the Hamiltonian analysis and relating it to a constrained scalar field coupled to gravity.

Contribution

It introduces a mimetic interpretation of disformal extensions of dRGT gravity, simplifying the Hamiltonian analysis and clarifying matter coupling possibilities.

Findings

Equivalent to dRGT gravity with a constrained scalar field

Simplifies Hamiltonian analysis of extended massive gravity

Provides insights into matter coupling in mimetic extensions

Abstract

An interesting proposal has recently been made to extend massive gravity models beyond dRGT by a disformal transformation of the metric. In this Letter we want to note that it can be viewed as a mimetic extension of dRGT gravity which enormously simplifies the Hamiltonian analysis. In particular, pure gravity sector is equivalent to the usual dRGT gravity coupled to a constrained scalar field. And we also give some comments about possible matter couplings.